My client has been using the email gateway for some years now.
About 6 months ago my client reported that emails would not send, they received a message saying Cannot send this item.After investigating I found it related to long URL's, once an email chain gets so long the links block the reply emails being sentWe use TOC via the email gateway, this is the cause of the issue as it rewrites the URL every time an email is sent even though it rewrote them previously.MS released a fix for this in April:https://www.bleepingcomputer.com/news/microsoft/microsoft-fixes-outlook-cannot-send-this-item-email-bug/This didn't resolve the issue my client is having, the fix may have been for 365 TOC.I have logged cases with support but not got anywhere, has anyone else seen this problem?
Same issue here, Sophos ToC creates URLs that are more than 2000 characters long, causing Outlook to show the "Cannot send this item" error instead of sending the email. I've contacted Support about the issue.
The above suggestion worked the URL safe list.
I don't understand. This is happening on external customer signatures. Are you suggesting we add all customer domains to the URL safe list going forward?